INVESTIGATION: Faeces burn through skin of 1 in 3 M&S and Sainbury’s chickens

NOTE: A version of this story first appeared in the Daily Mirror.

One third of M&S and Sainsbury’s chickens suffer from painful leg burns as a result of lying in their own waste, according to a survey by the AF News Agency and Viva!

What were the survey results?

City Branches surveyed Hock burned chickens Total chickens surveyed Hockburn %
London 2 12 25 48%
Edinburgh 2 16 37 43%
Bristol 3 26 84 31%
Cambridge 1 9 15 60%
Wolverhampton 2 3 30 10%
Peterborough 1 13 24 54%
TOTAL 11 79 215 37%
City Branches surveyed Hock burned chickens Total chickens surveyed Hockburn %
London 5 41 100 41%
Edinburgh 3 18 43 42%
Bristol 3 44 125 35%
Cambridge 2 17 34 50%
Wolverhampton 3 11 75 15%
Peterborough 0 0 0 NA
TOTAL 16 131 377 35%

What type of chickens were surveyed?

 – M&S Oakham standard whole chickens.
 – Sainsbury’s conventionally reared whole chickens.

Free range/organic/RSPCA approved etc were not surveyed.

What were they surveyed for?

The birds were examined for hock burns and marks i.e. brown and black lesions and discolouration on the legs (see image above).

For more photos click here.

What causes hock burns?

The ammonia in faeces, according to Professor Donald Broom.

Contact: Professor Broom
Tel: 0122 333 7697
Cambridge Emeritus Professor of Animal Welfare
Author of a 2005 hock burn study
Professor Broom is happy to be contacted.

How do the faeces get on their legs?

Carpets of excrement – according to Compassion in World Farming, industrial poultry sheds are only cleaned out after the birds have been slaughtered. So for the 5 – 6 weeks that the birds are alive the ground is laden with waste.

Nowhere to go – chickens naturally roost on perches. In factory farms they’re on the ground with the excrement.

No legs to stand on – In the last 80 years, selective breeding and high protein diets mean that chicken slaughter weights have more than doubled, while chicken slaughter ages have halved. This unnatural growth means that for many chickens their legs can’t support their weight and so they collapse into the waste. Accordingly heavier birds are more susceptible to burns.

No escape – The Red Tractor scheme, under which Sainsbury’s operates, and which covers most poultry farming in the UK, allows for around 17/18 birds per square metre (or about an A4 sheet of space). Hemmed in and unable to move, it means even those with strong legs tire and are forced to sit for long periods.

What do the results tell us about the supermarkets?

The suffering is systemic. M&S names the farmer who reared the chicken on their labels. Almost all the farmers whose birds were surveyed had hock burns.

Sainsbury’s doesn’t list the farmer. But using the EC codes on the label we were able to trace back where the birds were slaughtered. Of the four slaughterhouses we traced, one was in Lincolnshire and owned by Moy Park . The other 3 belonged to 2 Sisters, the country’s largest poultry firm, and were in Devon, Suffolk and Scotland.

According to the 2 Sisters’ website they source their chickens from farms near to the slaughterhouse. For each slaughterhouse, and therefore the farms in that area, there were multiple chickens with burns.

This means that’s it not just one bad apple – it’s the whole bushel.

Viva! quote: “It is appalling that so many British chickens suffer these painful burns, but it is sadly not very surprising. The vast majority are factory farmed in sheds with tens of thousands of others. Despite being killed at around just six weeks old, many will suffer the injuries this survey has shown because they spend their entire short lives on top of their own excreta. Many will develop leg problems because selective breeding means they are now much heavier than they were even compared to five years ago.  In the wild chickens would roost in trees, but there is no escape from the ammonia soaked floor in these industrial sheds.”

For more info contact: Justin Kerswell
0117 970 4632
Viva! Deputy Director

What do the supermarkets say?

They told the Mirror:

M&S – “Hock-marking is a challenge for all retailers and we work closely with our farms to reduce it.”

Sainsbury’s – “Suppliers are expected to comply with our code of practice and meet the high welfare standards our customers would expect.”

Click here for a list of supermarket and processor press contact details.

Both M&S and Sainsbury’s supposedly offer higher welfare than the standard Red Tractor. The Red Tractor guidelines (at page 11) state that hock burns should not normally exceed 15%.

M&S claims on its website that its Oakham chickens are stocked at 30 kg/m2 – significantly lower than the Red Tractor’s 38 kg/m2 i.e. their chickens have much more space.

Sainsbury’s doesn’t make any specific claims, merely that it has other welfare requirements in addition to Red Tractor’s.

However, despite this the survey results show that M&S chickens have a higher incidence of hock burns than Sainsbury’s.

Does that mean that M&S treats chickens worse than other supermarkets?

Not necessarily.

A 2005 Cambridge study found that 82% of supermarket chickens had hock burns. Since then the industry seems to have wisened up.

Tesco, Asda and Morrisons (Morrisons – excluding extra large birds) cut the hocks off. Without the hocks, there can be no evidence of hock burns. 

Meanwhile, Sainsbury’s chickens often have cuts on the hocks, precisely where the burns would have been.

Also, though M&S has a marginally higher overall hock burn rate,  the burns are less severe than Sainsbury’s.

It seems M&S treats its chickens less badly than other supermarkets, but is merely less adept at concealing their maltreatment.

Viva quote: “Perhaps what’s even worse than seeing the hock burns on these birds is the knowledge that rather than other supermarkets being any better, many of them hide their shameful track record by cutting away the affected part of the chicken.”

How was the survey conducted?

The survey was coordinated by AF News Agency, a start up news service focusing on farm animals. Volunteers from the Agency surveyed Edinburgh, Cambridge, Wolverhampton and Peterborough. Viva! Provided guidance and surveyed London and Bristol.

The cities were chosen on the basis of where volunteers lived.

Hidden cameras were used to record the survey taking and to verify location and date. The footage was then reviewed.

If you’re a journalist and would like to review our footage for yourself or if you have any questions, email

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s